title: Adrenergic regulation of cardiac ionic channels: role of membrane microdomains in the regulation of kv4 channels.
abstract: The heart must constantly adapt its activity to the needs of the body. In any potentially dangerous or physically demanding situation the activated sympathetic nervous system leads a very fast cardiac response. Under these circumstances, α1-adrenergic receptors activate intracellular signaling pathways that finally phosphorylate the caveolae-located subpopulation of Kv4 channels and reduce the transient outward K(+) current (Ito) amplitude. This reduction changes the shape of the cardiac action potential and makes the plateau phase to start at higher voltages. This means that there are more calcium ions entering the myocyte and the result is an increase in the strength of the contraction. However, an excessive reduction of Ito could dangerously prolong action potential duration and this could cause arrhythmias when the heart rate is high. This excessive current reduction does not occur because there is a second population of Ito channels located in non-caveolar membrane rafts that are not accessible for α1-AR mediated regulation. Thus, the location of the components of a given transduction signaling pathway in membrane domains determines the correct and safe behavior of the heart. This article is part of a Special Issue entitled: Reciprocal influences between cell cytoskeleton and membrane channels, receptors and transporters. This article is part of a Special Issue entitled: Reciprocal influences between cell cytoskeleton and membrane channels, receptors and transporters. Guest Editor: Jean Claude Hervé.
authors.affiliation: Lascaray Research Center, University of the Basque Country (UPV/EHU), Av. Miguel de Unamuno 3, 01006 Vitoria, Spain; Departamento de Fisiología, Facultad de Farmacia, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria, Spain. Electronic address: monica.gallego@ehu.es.
authors.forename: Mónica
authors.initials: M
authors.lastname: Gallego
authors.affiliation: Departamento de Fisiología, Facultad de Farmacia, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria, Spain. Electronic address: trofozoito2003@yahoo.es.
authors.forename: Aintzane
authors.initials: A
authors.lastname: Alday
authors.affiliation: Lascaray Research Center, University of the Basque Country (UPV/EHU), Av. Miguel de Unamuno 3, 01006 Vitoria, Spain; Departamento de Fisiología, Facultad de Farmacia, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria, Spain. Electronic address: hiartxu88@gmail.com.
authors.forename: Hiart
authors.initials: H
authors.lastname: Alonso
authors.affiliation: Lascaray Research Center, University of the Basque Country (UPV/EHU), Av. Miguel de Unamuno 3, 01006 Vitoria, Spain; Departamento de Fisiología, Facultad de Farmacia, University of the Basque Country (UPV/EHU), Paseo de la Universidad 7, 01006 Vitoria, Spain. Electronic address: oscar.casis@ehu.es.
authors.forename: Oscar
authors.initials: O
authors.lastname: Casis
mesh_terms: D000818:Animals; D006321:Heart / Q000502:physiology*; D006801:Humans; D007473:Ion Channels / Q000378:metabolism*; D021962:Membrane Microdomains / Q000378:metabolism*; D018340:Receptors, Adrenergic, alpha-1 / Q000378:metabolism*; D051672:Shal Potassium Channels / Q000378:metabolism*
chemical_list: D007473:Ion Channels; D018340:Receptors, Adrenergic, alpha-1; D051672:Shal Potassium Channels
keywords: Arrhythmia; Compartmentation; Heart; K(+) channel; Raft